Fully digital control and drive combination IC with on-board DSP for disk mass storage device

A combo device for driving and controlling a rotation motor and a voice coil motor of a disk mass storage drive comprising

• a digital signal processor (DSP) functioning in a time sharing mode in carrying out a plurality of functions,
• a programmable memory and at least a work memory (XRAM, YRAM),
• a bank of input/output registers (AS_DSP REGISTER BANK),
• memory address decoding circuits (ADDRESS DECODER),
• a circuit controlling and driving a multiphase motor that rotates the disk (SMOOTH-DRIVE),
• a timing block (SCHEDULER),
• an output stage (VCM POWER) driving a “voice coil” motor for positioning a swinging arm carrying at least a read/write head, controlled in switched mode by a generator (PSM GENERATOR) of two control phases of variable duty-cycle
• a duty-cycle control loop comprising a current sensing circuit (VCM CURRENT SENSING), and
• a control loop of the position of said arm comprising a speed detection circuit (VCM SPEED SENSING), characterized in that
• said two control loops are digitally implemented by said digital signal processor (DSP) in function of digital data representing an analog signal representative of the current flowing in the winding of said “voice coil” motor generated by said current sensing circuit (VCM CURRENT SENSING) and an analog signal representative of the instant speed of said “voice-coil” motor generated by said speed detection circuit (VCM SPEED SENSING);
• the device further comprising a multiplexer (ANALOG VIN MUX) of selection among said two analog signals and a third analog signal representative of the drive current of said multiphase motor that rotates the disk;
• a single analog/digital converter (ADC) functionally coupled in cascade of the output of said multiplexer (ANALOG VIN MUX) and means for switching the output of said analog/digital converter towards respective registers of said bank (AS_DSP REGISTER BANK);
• a serial interface with an external bus (SERIAL AND CONTROL INTERFACE) of communication with an external controller.